According to the World Health Organization, an estimated 39 million people worldwide are blind. In the United States, 1.2 million people are legally blind and −10% of them are functionally blind. Their numbers are projected to grow in the coming decades. Although blind people can access text through braille and text-to-speech, mobility indoors and outside is limited, dangerous, and largely depends on the long cane. Blindness also limits numerous other activities of daily living, particularly tasks requiring visual search and object recognition. As a result, many pursuits (vocational and social) are limited, especially for the acquired blind whose blindness occurs in adulthood. Restoration of vision through prostheses is expected to address many of these difficulties.